I honestly can't stand seeing this topic come up. And it's always the same story. "It's too hard to use and so sloooooow". And every time I feel like responding the same way i.e. go try and do literally anything on a Wii U other than just launching a game and then come back to me saying the Xbox UI is slow or sluggish. What a load of nonsense. I will take the Xbox UI any day over something like the Switch which is so barebones it may as well not exist, and even that needs to constantly do things like reload the eShop each time you want to use it and has no multitasking to speak of. Meanwhile here i am streaming music from my Onedrive at the same time as playing multiplayer games online and the guide is fast and snappy enough that doing things like changing tracks or adjusting the volume can be done without me skipping a beat (or getting killed).
As for this not knowing where to find captures thing, considering you can get to it from at least 3 different ways i find it hard to believe that you genuinely struggle unless you are purposefully avoiding any prompts or onscreen guides/iconography. Off the top of my head it's Guide - View (Select if you're old school) - Manage captures (takes all of 2 seconds) for everything, Guide, RB twice and Recent captures for, you guessed it, recent captures and if it's not recent enough you can hit "See all" and that takes maybe 5 seconds unless you have arthritis. You can also get to it from your profile card which is a longer journey but even that is 10 seconds if you know how to navigate it. You're telling me you've never read the text on the bottom of the screen when you press Guide or you have never navigated to the Broadcast/captures tab? Ok then.
How, exactly, do you propose they make this any faster or easier to find? Unless your solution is "have a physical hardware button dedicated to it" then by all mean, share your solution.